If the mean vector QRS axis is -90 or +90 degrees, lead I is likely gonna be near isoelectric cause it's perpindicular to lead I (lead I is left to right, mean vector QRS axis is going up (-90 degrees) or down (+90 degrees). It's not going towards the positive electrode for lead I (left arm, black electrode), which would make it a positive QRS complex, nor away from the positive electrode for lead I (away would be towards right arm electrode, the white one), which would make a negative QRS complex (if the mean QRS complex would be going towards the right arm lead, the white one). I believe I saw it was +89 degree in the image yesterday, but I'm on my phone so I'm too lazy to actually load the image to look at it.
I believe it did meet one of the left ventricular hypertrophy (LVH) voltage criteria per Thomas Garcia's Art of Interpretation, which is aVF is greater than or equal to 20 mm I think? It's not a normal criterion I hear or seen used. To be honest, for LVH by itself, I would expect the mean QRS vector axis to be close to the left because of an obviously large left ventricle, but there are other things that could cause the axis to shift eg hypertrophic cardiomyopathy (HCM) or something electrical eg fascicular block/hemiblock.
I do not suspect hypokalemia. I think the p-wave is very visible. I don't recall seeing a second lump on the t-wave or in the TP segment that would make me think u-wave.
Interestingly I recall I think I saw retrograde T-wave and downsloping in III, a small q-wave in III, and small S-wave in I. S1Q3T3 I believe is a sign of right ventricular strain pattern including the downsloping in III looked like a strain pattern so maybe HCM, but to be honest, don't like thinking about these things without a 12-lead, and if you start to look too deeply in 12-leads, you gonna start seeing stuff that's not there (pareidolia, just read a yahoo article on this
) eg looking at the moon and seeing a face. I don't like to overthink ECGs.
To be honest, I see S1Q3T3 all the time for some reason now. I dislike it.
I would take a 12-lead just because they had a seizure. Electrolytes and arrhythmia are gonna be in my head for seizure patients.